More than a decade ago, sisters, Katherine and Kimberly Corp opened Pilates on Fifth in a 5,000-square-foot penthouse high above the core of midtown Manhattan. Though the tiny crowds on the streets below continue to bustle through their busy lives, the sprawling studio's mission has remained steady: aided by equipment such as reformers, Cadillac chairs, and barre bars, a staff of instructors coaches and motivates students as they build strength and balance in a variety of classes. With backgrounds ranging from stints with the Rockettes to studies in sports medicine, the teachers lead groups in everything from CoreAlign—a fast-paced flow of aerobic workouts that help strengthen the core to their newest class addition, SilkSuspension. In this class, clients can get a total body workout by performing exercises while suspended from aerial silks. Kimberly and Katherine started online video workouts back in 2008, and have accumulated over 150 workouts in the process. All workouts can be sorted by length, level, body part targeted, and prop, so that you can fit your exercises into the busiest of schedules.